Alcohol-soluble azo dyestuffs and their manufacture



Patented May 16, 1944 UNITED STATES PATENT OFFICE ALCOHOL-SOLUBLE AZO D'YESTUFFS AND THEIR MANUFACTURE Achille Conzetti, Basel, and Ernst Lehmann, Riehen, near Basel, Switzerland, assignors to J. R. Geigy A. G., Basel, Switzerland, a Swiss firm No Drawing. Application April 21, 1942, Serial No. 439,922. In Switzerland January 21, 1941 12 Claims. ('Cl. 260-144) It has been found that new valuable, alcoholcompounds consisting only of basic and acid dyesoluble dyestufi salts are obtained by precipitatstuiis. ing azo dyestuffs, more particularly azo dyestuffs The present invention is illustrated by the folof the benzene, naphthalene and pyrazolone selowing examples, without being limited thereto.

ries, which contain water solubilising acid groups T e pa ts are y Weight. 11111888 Otherwise Statedand at least one hydroxy group acylated by an aryl sulfonic acid, with basic dyestuffs from the. w i 1 series of the yellow to red dyestufis. The new CH3 water-insoluble compounds are distinguished from similar known dyestuif salts obtained from acid and basic dyestuffs by an improved solui G- bility in alcohol, by a better fastness to light and generally by purer shades. Also when com- OH pared with improved dyestufi salts which contain complex metal compounds and thus cannot directly be compared therewith, the compounds prepared according to the present invention have been proved superior with respect to solubility, to purer shades and in some cases also to light fastness.

It has furthermore been found that by using azo dyestuils containing several sulfonic acid groups and requiring therefore more than molec- C -O- O- ular quantities of basic dyestuff for causing precipitation, a part of the basic dyestufis may be replaced by other organic bases which are also suitable for the precipitation of acid dyestuffs.

In connection therewith it is advantageous to use at least molecular quantities of .basic and acid dyestuffs whereby a sulfonic acid group of the azo dyestufi is connected with the basic dyestuiT; the remaining sulfonic acid groups are reacted with the other organic bases known for the precipitation of acid dyestuffs.

.As organic bases, those of the aromatic series 5 such as aniline, toluidines, xylidines, aminodiphenyl compounds, their substitution products, aryl guanidines, aryl biguanides and so on, are primarily useful. An extensive enumeration is superfluous, as a great number of such compounds has become known for the same purposes parts of this dyestuff are dissolved hot in 2500 parts of water, then the solution is filtered, if necessary, and precipitated at -70 C. with a solution of 72 parts of rhodamine 6G extra (Schultz, Farbstofitabellen, 7. Auflage, No. 866) in 1880 parts of water and 36 parts of acetic acid When the precipitation has completed, stirring is continued for an additional 15 minutes and the whole is filtered.

The new yellow-brown, crystalline compound dissolves, already in the cold, in alcohol in a quantity of 10% and more and dyes cellulose very good light fastness.

When the acid dyestuff is precipitated out by means of rhodamine B (Schultz No. 864), a crystallised, brown powder is obtained, the solubility n e e t e p y in the P t t of which is remarkable already in the cold. Also erature. other rhodamine dyestuffs of the trade, such as Owing to the diminution of the basic dyestuff for example rhodamin G, 33 01- 3G are also component the shade of these alcohol-soluble suitable. dyestufis approaches rather that of the acid The dyeings in cellulose ester lacquers are discomponent. The properties, especially the fasttinguished, besides a good light fastness, by an ness properties are just as good as those of the extremely high purity and brilliancy.

ester lacquers with a pure orange coloration of a Example 2 SOaH SOaH

red colorations of excellent light fastness. When compared with a similar compound obtainable from chrysophenine (Schultz No. 726) and rhodamine B, the precipitation prepared according to the above example is by far faster to light, purer with respect to the coloration and much better soluble in alcohol. The chrysophenine lacquer is difficultly soluble in alcohol; also in other usual solvents and cellulose ester lacquers large residues remain so that a practical use does not come into question. From this comparison it results that the phenolic hydroxyl group esterified by an aryl sulfonic acid is the cause for the surprising improvements of the properties of the compounds made according to the present invention. This fact is the more surprising, because just alkoxy groups have become known as very suitable substituents for dyestuffs with an excellent solubility in organic solvents.

In the following table some further compounds are enumerated which can be produced according to the process indicated in the above examples:

Dyeing Basic dyestufi Dyeing Rhodamine 66-. Rhodamine B... Rhodaminc B... Rhodamine B... Rhodamine 6G Rhodamine 6G..

Yellow-orange. Blue-violet. Red-violet. Bluish-red. Eosine. Yellow-red.

e Yellow-orange.

Yellow.

Rhodamine B... Rhodamine 6G. Yellowish-red. Seto-flavine T Yellow-orange. Rhodamine B... Blue-red.

Rhodamine B... Bluish-red. Rhodamine 6G.. Red. Auramine O... geg-orange.

Rhodamine B... e Rhodamine 6G. Yellowish-red.

Bluish-red.

Auramine 00.... Yellow-brown.

is soluble, in the cold, in alcohol in a quantity of 10% and more. The dyeings are water-fast and of excellent light fastness, a fact which is very surprising, when it is considered that 65-70% of this new compound consists of a basic dyestuff which is not fast in itself.

If the precipitation is effected with rhodamine B (Schultz N0. 864), there is also obtained a crystallised brown compound of excellent solubility whose beautiful, pure red colorations show an unobjectionable water fastness and a very good light fastness.

Also auramine O0 (Schultz No. 752) produces a precipitation which is soluble in cellulose ester lacquers with a beautiful, yellow color. The light fastness is also excellent.

Example 3 tdl l 100 parts of this technical dyestuff are dissolved hot in 2000 parts of water and precipitated at 6040 C. with a solution of 90 parts of rhodamine B'extra in 1500 parts of water and parts of acetic acid 80%. The crystalline compound shows remarkable solubility in alcohol and produces for example in nitrocellulose lacquers pure Here also the .other rhodamine dyestuffs still mentioned in Example 1 come equally well into consideration,

Constitutions of the acid dyestufis No. 4-13 (4) NmQ-NH-ONm-Qosm-Omm s 03H I OH CHE-OS 0,. OON=NQN=N 0311 NH] s 03H HOaS SOaH

SIOIH 11) p HO oso CH3 1 osm-Qm Eicample 14 parts of the dyestuff SOaH scan are combined at 50 0., in form of a solution of 4% strength, with a solution of 4% strength of 10 parts of rhodamine 6G extra. Then the whole is allowed to cool down to 30 C. and a'solution of 10% strength containing 6 parts of p-toluidine, 6 parts of phenyl biguanide and 12 parts by volume of acetic acid of 80% strength is gradually added thereto. At the end the temperature is again raised to C., whereby the precipitation is converted intoa fine powder form. It is finally filtered off and washed. 43 parts of a brownpowder are obtained, 10 per cent of which are soluble in alcohol andnitrocellulose lacquers. The Shade of the lacquer dyeings is somewhat yellower than that of the corresponding .dyestufiw'hich is only prepared from an acid and 'basic dyestuffv, but the light-fastness is just as good.

Example 15 9 parts of aux-amine 00000 and 1 part of rhodamine 6G extra are dissolved in 250'pa'rts of Instead of the toluene, benzene or chlo'rdben- .zene sul'fonyl'radicals"inthe'aboveexamples, also other sul'foni'c acid radicals of .benzene com- ;pounds with neutral 'substituents (halogen, alkyl, --alkoxygroups and .therlike) may equally well 'be i practical :reasons (cheapness) .the hydro"carbon isulfonyl radicals are preferred.

' soin water and this solution is slowly added, while thoroughly stirring, at C. to a 4% solution of the acid dyestufi according to Example 14. Then the temperature is allowed to sink to 30 C., whereupon the mixture is gradually treated with loo-parts by volume of a solution containing 5 parts of p-toluidine, 5 parts of phenyl biguanide and parts by volume of acetic acid of 80%- strength. It is advantageous to finally raise the temperature to 45 0., whereby the separation form is favourably influenced. After filtration and drying, 40 parts of an orange brown powder are obtained which possesses the same properties as the alcohol-soluble dyestuff according to Example 14.

Instead of the acid and basic dyestufis used in Examples 14 and 15 there may quite well be used-the compounds mentioned in Examples 1 to 3 and in the table, Examples 4 to 13.

Instead of p-toluidine and phenyl biguanide there may quite well be used other bases known for the precipitation of acid dyestuffs, such as for instance diphenyl guanidine, di-o-tolyl guanidine, cyclohexyl phenyl amine, dicyclo hexylamine, dodecyl amine and so on.

What we claim is:

1. Process for the manufacture of alcoholsoluble dyestuffs wherein an acid azo dyestufi selected from the class consisting of azo dyestuffs of the benzene, naphthalene and pyrazolone series and containing at least one hydroxy group a'cylated by a aryl sulfonic acid of the benzene series, is precipitated with a basic dyestuff selected from the rhodamine and ketonimine dyestufi series.

' 2. Process for the manufacture of alcoholsoluble dyestuffs wherein an acid azo dyestufi selected from the class consisting of azo dyestuffs of the benzene, naphthalene and pyrazolone series and containing at least one hydroxy group 'acylated by an aryl-sulfonic acid of the benzene series and more than one sulfonic acid group is precipitated with at least an equimolecular part of a basic dyestuff selected from the rhodamine" and ketonimine dyestuff series and with a basic organic compound capable of precipitating said acid dyestuff.

3. Process for the manufacture of alcohol-soluble dyestuffs wherein an acid azo dyestufi selected from the class consisting of azo dyestuffs of the benzene, naphthalene and pyrazolone series and containing at least one (p) CH3.CeI-I4.SO2.0-

- is precipitated with rhodamine 6G.

5. Process for the manufacture of an'alcoholformula soluble dyestuff wherein the dyestuff of the for? mula 1 v 1 x is precipitated with rhodamine B.

6. Process for the manufacture of an alcoholsoluble dyestuff, wherein the dyestuff of the formula HO ism-Own is precipitated with rhodamine B.

'7. The alcohol-soluble dyestuffs of the general formula A(SO3H)1L.B1I

the general wherein A means the radical of an acid azo dyestufflselected from the class consisting of azo dyestuffs of the benzene, naphthalene and pyrazolone series, connected with the n sulfo groups and substituted by at least one hydroxy group acylated by an arylsulfonic acid of the benzene series, B means a basic dyestufi selected from the rhodamine and ketonimine dyestuft series, C means a basic organic compound capable of precipitating said acid dyestuff, n means the number of sulfonic acid groups present in the acid dyestufllbeing at least 2, a: means at least 1, being inuall cases smaller than n, said dyestuffs being yellow to red and violet compounds insoluble in water, yieldingj colored lacquers of excellent light fastness.

9. The alcohol-soluble dyestuffs of the general where Az means the radical of an acidazo-dyepyrazolone series, connected with then-toluene sulfonyloxy group and the n sulfo groups, R

means the molecule of a rhodamine dyestufi and n means one of 1, 2 and 3, being orange to red and violet compounds insoluble in water, yielding colored lacquers of excellent light fastness.

10. The alcohol-soluble dyestufi of the following formula being a brown powder, insoluble in water, yielding colored lacquers of pure orange color of excellent water and light fastness.

11. The alcohol-soluble dyestuff of the following formula S 0 H 8 0 3H [rhodamine B],

being a brown powder, insoluble in water, yielding colored lacquers of pure red color of excellent water and light fastness.

12. The alcohol-soluble dyestuff of the following formula r to osoOoHs rhod- I 1103s s0=H L amine B being a dark powder, insoluble in water, yielding colored lacquers of bluish red. color of excellent fastness properties.

ACHIILLE CONZETTI. ERNST LEI-IMANN. 

